1. Field of the Invention
The present invention relates to an open/close mechanism of a door applicable to a variety of cars such as cars used in a guided transit system to open the door in a time of emergency to enable passengers to escape easily from the train.
2. Description of the Related Art
Emergency doors of cars used in a guided transit system are generally provided at the front or rear end of the vehicles. In these years, a medium capacity transit system, one of so-called new transit systems, in which guided train equipped with rubber tires travel along exclusive guideway, has become widespread. Full automatic operation of unmanned train is performed in many of these transit systems. In these systems, generally an automated vehicle or combination of automated vehicles runs along the exclusive guideway.
Emergency doors of the cars used in the new transit systems are single swing ones. The door must extend in straight line about hinges so that the door is opened by swinging it. Even when the front end of the leading car is of a curved surface, the door must extend in straight line about hinges, it protrudes inevitably from the curved surface.
In patent literature 1 (Japanese Laid-Open Patent Application No. 5-10049) is disclosed a single swing emergency door applied to vehicles such as buses.
In patent literature 2 (Japanese Laid-Open Patent Application No. 2002-339639) is disclosed an open/close mechanism of an emergency door of a vehicle used in the new transit systems, etc. According to the disclosure, an upper and lower hinge bracket are attached to the carbody and an upper and lower hinge bracket are attached to the emergency door, each of these hinge brackets has a vertical through hole to accommodate a hinge pin, two hinge pins inserted into the through holes of the upper hinge brackets are fixedly connected by an upper bent arm, and also two hinge pins inserted into the through holes of the lower hinge brackets are fixedly connected by a lower bent arm, and the door can be turned about the center line of each of the through holes of the upper and lower brackets attached to the carbody. With this configuration, the emergency door can be opened horizontally without moving it against gravitation.
In patent literature 3 (Japanese Laid-Open Patent Application No. 2007-63789) is disclosed a subsidiary open/close mechanism of door applied to a microbus, etc. The subsidiary open/close mechanism is composed such that the door is supported by two bent arms connected to the door at an upper and lower position rotatable with respect to the carbody and also supported by two link bars located laterally, so that the door can be moved horizontally to open/close the entrance of the bus.
The single swing emergency door of the patent literature 1 is opened outward and requires a certain space outside the carbody to open the door. Therefore, when it is provided at an end of a coupled with another vehicle, the door may interfere with the end face of the adjacent vehicle when opening the door. Further, when the emergency door is attached to a curved profile of front face of leading car, hinges protrude outside the body, and sealing of the mating part of the door and the carbody is difficult, which tends to induce occurrence of ingress of rainwater. Further, when the front end of a leading car is of a streamlined form having a sweepback angle, the hinge line must be slanted, so it is inevitable that the emergency door is a one opened upward and fairy large force is required to open the emergency door against gravitation.
The emergency door disclosed in the patent literature 2 is moved horizontally along the outer face of the carbody of leading car, so it has an advantage that not large space is required at outside the carbody as compared with the case of the single swing door. However, supporting of the door by the arms is not stable, the door tends to rotate, and there are concerns that the door impinges against the carbody and damages the carbody.
In the mechanism disclosed in the patent literature 3, the door is supported by four supporting bars, i.e. two bent arms connected to upper and lower part of the door and two lateral link bars, so its configuration is complicated, and as a stopper mechanism of the door is not provided, it is considered that the door impinges against the outer face of the carbody and damages the carbody.